介词的基本用法与习惯搭配He came back late, ________ which time all the guests had already left
Even the best writers sometimes find themselves __________ for words.
I am afraid he's more of a talker than a doer, which is __________ he never finishes anything.
Claire had her luggage __________ an hour before her plane left.
His father got very __________ when he made a mistake again.
The young teacher says this is __________ for the beginners.